<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8"/>
    <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
    <title>Document</title>
</head>
<body>
    <ul>
        <li id="l1" class="cc">北京</li>
        <li id="l2">上海</li>
        <li id="c2">广州</li>
        <li id="c3">深圳</li>
    </ul>

    <ul>
        <li id="l1">天津</li>
        <li>哈尔滨</li>
        <li>贵州</li>
        <li>云南</li>
    </ul>
</body>
</html>